ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-87866

When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess.

Published Oct 20, 2026 · catalog updated Oct 25, 2026 · When built with wolfSSL,

Last checked Oct 25, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-87866. EPSS is 0.17%. Act only if a listed version of When built with wolfSSL, is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (When built with wolfSSL,).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.17%
Remediation
Advisory link
Affected products
Alpine:v3.23 curl · Alpine:v3.24 curl · vendor curl curl

When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity length field - extracts and matches a different embedded key, incorrectly authorizing the pinned public key.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Alpine:v3.23 curl0 → 8.23.0-r0
  • Alpine:v3.24 curl0 → 8.23.0-r0
  • vendor curl curlversion unspecified

How to fix CVE-2026-87866

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-87866. EPSS is 0.17%. Act only if a listed version of When built with wolfSSL, is installed.

Which versions are affected?

Compare what you have installed with 0 → 8.23.0-r0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.17%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 20, 2026 · NIST NVD

    Detected

    When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity length field - extracts and matches a different embedded key, incorrectly authorizing the pinned public key.

  2. Oct 22, 2026 · NIST NVD

    Updated

    When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity length field - extracts and matches a different embedded key, incorrectly authorizing the pinned public key.

  3. Oct 25, 2026 · Trivy Vulnerability DB

    Fix available

    curl fixed in 8.23.0-r0; curl fixed in 8.23.0-r0

  4. Oct 25, 2026 · Trivy Vulnerability DB

    Fix available

    curl fixed in 8.23.0-r0

  5. Oct 25, 2026 · Trivy Vulnerability DB

    Updated

    When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity length field - extracts and matches a different embedded key, incorrectly authorizing the pinned public key.

Sources

  • CVE.orgVulnerability recordCVE-2026-87866

    When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity l

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-87866

    30-day exploitation probability 0.17%

    first.org
  • NIST NVDVulnerability recordCVE-2026-87866

    When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity l

    nvd.nist.gov
  • Trivy Vulnerability DBPackage advisoryALPINE-CVE-2026-87866

    When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity l

    osv.dev

References

Freshness

Last verified in this catalog Oct 25, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • Trivy Vulnerability DBOct 25, 2026
  • FIRST EPSSOct 25, 2026
  • CVE.orgOct 23, 2026
  • NIST NVDOct 22, 2026